Ionisation and charge-transfer cross sections for H⁺, He²⁺+He⁺

The classical-trajectory Monte-Carlo method has been used to calculate the ionisation and charge-transfer cross sections for the H + , He 2+ +He + systems in the energy range 100-500 keV amu -1 . For the H + +He + system, the sum of the calculated ionisation and charge-transfer cross sections is found to lie uniformly about 40% higher than the measured values of Angel et al. (1978). However, for both systems the classical-trajectory values are in good agreement with calculations based on the Born and binary-encounter approximations at the higher collision energies.